The provision of preprinted forms in an interconnected manifold set or layered assembly, composed of record forms, carbonless copying sheets, or record sheets with transfer sheets or carbons interleaved therebetween, is customary in modern business practice. It has been found most efficient to produce this type of assembly in a continuous form wherein the layered assembly is made severable along its length into a plurality of separate units by transverse perforations and also, by virtue of which, these units, corresponding to manifold sets of separate forms, are capable of being stacked conveniently in continuous zig-zag manner, for storage or transport.
Surface deformation in the several superimposed sheets of each assembly of the zig-zag stack will, unless some provision is made for flexible movement of the member sheets with respect to each other, tend to occur with consequent damage or distortion of the stacked or rolled assemblies. Deformation of the manifold assemblies of superimposed business forms, where the interconnection between the several sheets of the assembly is fixed or rigid, will also occur where the layered assemblies are forced about the feed rolls or cylindrical platens of varying diameters occurring in the many different business machines, including, for example, mini-computers, with which they are used increasingly. But whatever the particular deformation, either in storage, handling or use, the individual sheets or webs, tend, in this event, to shift longitudinally with relation to each other and must be free to do so. This interconnection or fastening of individual sheets in layered assembly occurs conventionally along the lateral margins of the superimposed sheets or webs using a variety of adhesive, crimping, and other techniques well-known to those skilled in the art.
Accordingly, if gluing, or other conventional, but less frequently employed means, such as stitching, stapling (which is capable of causing serious injury to a computer mechanism in which the manifold assembly is used), or the like, is employed to effect an immovable or inflexible fastening in which the superimposed sheets cannot shift longitudinally in relation to one another along the lateral margins of the superimposed sheets they cannot be folded or bent without buckling, distortion or even tearing of the forms. This much is well-recognized in the art and various means have been used or suggested to provide a more flexible fastening means capable of maintaining the condition of alignment of the assembled forms while accommodating the need for a longitudinal shift and a consequent, but reversible, misalignment to accompany deformation. At the same time, attempts have been made to reduce the bulkiness introduced into the assembly by gluing, stitching and other interlocking expedients incorporating foreign materials and rigidity into the assembly.
One means for maintaining the sheets or manifold assemblies in the necessary condition of alignment, while leaving the individual webs free to undergo shifting movement to avoid damage and internal stress, provides a series of crimps in the lateral margins of the assembly sheets. These crimps take the form of a series of marginal tabs or tongues, the free ends of which are depressed from the plane of the individual sheets to form interlocks based on this displacement. This expedient lacks permanence and stress tends to separate the several superimposed layers of an assembly so interconnected.
Another approach which is uniquely adaptable to manifolds, including record sheets and interleaved transfer or carbon copies, is that in which adjacent forms or record sheets bear continuous glue streams. The alternating transfer or carbon sheets, usually of relatively fragile integrity are bonded by means of the adhesive to both the underlying and overlying record sheets or strips using the foregoing glue streams. One or more series of marginal stress-relieving slits are provided in certain embodiments of this construction in the margin of the carbon sheets adjacent the paths of the record strip bonds to afford the desired adjustment to shifting. This construction thus retains the disadvantages, particularly of bulk and rigidity, of a more or less continuous glue stream and is, in any event, advantageously employed, it is believed, only where carbons are alternately interleaved in the manifold assembly. Additional disadvantages inherent in this latter expedient are the requirement of special and onerous additional production steps and equipment to make the stress-relieving slits in the carbon sheets, which results in additional expense in production of the forms and which, at the same time, weakens the carbon construction and renders it vulnerable to stress and damage by tearing and the like.
A further expedient proposed heretofore employs a combination of tab-formation and adhesive wherein a tongue is struck up from one exterior sheet vertically through holes provided in registry in the one or more intermediate sheets to pass outwardly onto the outer surface of the opposite exterior sheet to which the tab is made to adhere by gluing of the underside of the tab to the surface of the sheet. The tab may be further extended to double-back through a second series of orifices, as well. A further embodiment of similar aspect, described heretofore, suggests that the tabs lanced from one exterior sheet of an assembly be glued along their free underlying surfaces, after passing through a series of holes in registry in the intermediate sheets, to the interior surface of the opposing exterior sheet. The opposing exterior sheet is otherwise unmodified for this purpose. Alternatively, tabs may be formed on the opposing exterior sheets and made to pass through the holes of the intermediate sheets to adhere to the opposite surface of a centrally disposed sheet in the assembly. This latter sheet is unmodified for the purpose of forming an interlock, except for the adhesive disposed on its opposite surfaces between the fastening tabs.
The latter expedients require several additional steps and apparatus in preparation; for example, one or more punch units for the tab or tabs of each fastening point, a punch unit for the holes of the intermediate sheets or web and one or more special pressure units to push the tab or tabs through the holes in combination with a glue device. Further, the foregoing tab connectors are not adapted to permit the release of single sheets in series from the assemblies.
In the event, therefore, that means could be devised which would provide for high speed production of manifold assemblies, the superimposed sheets of which were fastened to one another by a combination of crimping and adhesive and in which the adhesive is used in minimal amounts consistent with the optional separation or decollation from the assembly of individual sheets and in which each crimp fastening required only a single crimp module, in combination with a single glue device while permitting the requisite alignment, and longitudinal shifting during assembly deformation, a significant advance in the state of the art would be attained.
It is, accordingly, an object of this invention to provide a plurality of continuous superimposed webs or sheets of flexible material, flexibly and permanently interconnected in manifold assemblies in a condition of alignment which permits the individual sheets to engage in, at least, a longitudinal shifting movement with respect to one another when the planar configuration of the assembly is disturbed to avoid stress and damage to the assembly and a return to a position of alignment when the planar state is restored.
It is a further object of this invention to provide manifold assemblies from which individual sheets or forms can be severed in series or decollated without materially affecting the fastening of the remaining sheets or forms therein.
It is still a further object of this invention to provide a high speed method and correspondingly efficient conventional apparatus with minimal but significant modification for producing the interlocked manifold assembly of the invention.